1. Field of Invention
This invention relates generally to imaging, and more particularly to controlling a common visible characteristic of an image element in response to amounts of reflected energy at respective different frequencies.
2. Description of Related Art
One known imaging technique is sonar, which is an acronym for “sound navigation and ranging”. Known sonar techniques use propagation of sound through a medium such as water, for example, to measure location, shape, and other characteristics of objects that reflect sound, such as an ocean floor or objects on the ocean floor, for example. Conventional sonar devices may transmit a brief acoustic pulse, which may be referred to as a “ping”, and over time receive and measure amounts or intensities of reflected energy from the acoustic pulse. Having regard to the speed that sound travels through the medium, the measured amounts or intensities of reflected energy over time may indicate respective distances or other characteristics of one or more reflective objects from a reference point.
One consideration for sonar or other reflected energy imaging applications is identifying an appropriate frequency of the energy to be transmitted, reflected, received, and measured. For example, in a sonar system for imaging in water, a lower frequency may facilitate imaging over a longer range, but a higher frequency may provide overall higher image quality. Disadvantageously, many known imaging devices require choosing a single frequency for use in generating an image, and therefore necessarily produce an image having the inherent disadvantages of the chosen frequency.